RFR: 8229957: Harden pid verification in attach mechanism

[Yasumasa Suenaga]

Hi Leonid,

In case of Linux on Docker container, java might be run with PID=1.
So I think `pid <= 1` is incorrect.


Thanks,

Yasumasa


On 2019/08/21 8:32, Leonid Mesnik wrote:
> Hi
> 
> Could you review following fix which add sanity check of pid value in
> attach mechanism on *nix based platforms.
> 
> PID for java process is always positive on affected OS. Hotspot
> internally uses signal (SIGQUIT) while attaching. So using negative
> numbers as pid might cause very unexpected results and should be prevented.
> 
> webrev: http://cr.openjdk.java.net/~lmesnik/8229957/webrev.00/
> 
> bug: https://bugs.openjdk.java.net/browse/JDK-8229957
> 
> I checked that jcmd doesn't allow to connect to negative pids.
> 
> Leonid
>